Photographically useful latexes
Some prior photographic uses of latexes involved their use as a source of a polymeric ingredient in coated layers. Martinez et al. (U.S. Pat. No. 2,269,158), Donn et al. (U.S. Pat. No. 3,518,088), and Van Campen (U.S. Pat. No. 3,619,195) disclose the codissolution of photographically useful hydrophobes and polymeric latexes in organic solvent, prior to being formulated into the remainder of the coating composition. The latex particles that resulted from such formulations were generally large, and even after being subjected to colloid milling procedures were from 1 to 2 microns in diameter.
Burk discloses (U.S. Pat. No. 2,500,023) a method of incorporating small quantities of dye or pigment in latexes, by mixing the dye or pigment with the monomeric precursors and a polymerization initiator. The highest level of incorporated dye or pigment obtained by this method was 0.5% (w/w) of the total casting syrup. Millikan discloses (U.S. Pat. No. 3,418,127) a similar process for incorporating fluorescent components in a latex.
Tong discloses (U.S. Pat. No. 2,772,163) a method of forming finely divided colloidal suspensions of couplers by dissolving them in alkali and, optionally, alcohol, mixing the coupler solution with a latex, and then adding acid to precipitate the coupler in particulate form. More finely divided dispersions of coupler were obtained by this method than were obtained in the absence of the latex.
Cohen et al. (U.S. Pat. Nos. 3,898,088 and 3,944,424) disclose the preparation of polymeric mordants for photographic elements, in which dyes are immobilized on the polymeric mordants.
Upson and Steklenski disclose (U.S. Pat. No. 4,544,723) latex compositions containing vinyl acetate polymers that have excellent adherence to film supports such as cellulose acetate.
Schofield et al. (Eur. Pat. Application 190003 A2) disclose the formulation of latexes of homopolymers or copolymers of vinyl-substituted UV filter dyes by emulsion polymerization methods.
It is well known in the art of color photography that color images are produced by a colored dye which is formed by a coupling reaction between an oxidized product of an aromatic primary amine color developing agent and a coupler. Various types of cyan, magenta, and yellow dye-forming couplers are well known for use in such coupling reactions. For example, a coupler of the acylacetanilide or benzoylacetanilide type may be used for forming yellow dye images, a coupler of the pyrazolone, pyrazoloazole, pyrazolobenzimidazole, cyanoacetophenone or indazolone type may be used for forming a magenta dye image, and a coupler of the phenolic or naphtholic type may be used for forming a cyan dye image.
It is also known in the art that the coupler may be in the form of a polymer which improves the ability of the dye to remain in the location where it is formed in a color photographic element. For example, Monbaliu et al. disclose (U.S. Pat. No. 3,926,436) photographic elements containing polymeric couplers as latexes which show less foaming tendency and which show high compatibility with hydrophilic colloids such as gelatin. Yagihara et al. (U.S. Pat. No. 4,474,870) disclose photographic materials containing polymeric coupler latexes that form magenta dyes upon coupling with oxidized developing agents. Hirano et al. (U.S. Pat. No. 4,511,647) disclose color photographic materials containing cyan color forming coupler latexes. Yagihara et al. (U.K. Pat. No. 2,092,575 B) disclose silver halide photographic materials containing magenta color forming coupler latexes. Cawse and Harris (European Pat. Application 0321399 A3) disclose a method of preparing latexes of color couplers.
Generally, three methods have been employed in the past for dispersing polymeric couplers. These three methods include (1) dispersing the coupler by colloid milling or homogenization methods, along with high and/or low vapor pressure organic solvents in aqueous surfactant and gelatin; (2) direct incorporation of solutions of water soluble polymers; (3) latex formation by emulsion polymerization or suspension polymerization.
Hirano (U.S. Pat. No. 4,522,916) discloses the preparation of polymeric magenta dye forming coupler latexes that provide images of improved light stability. Hirano and Furutachi (U.S. Pat. No. 4,576,910) disclose the preparation of polymeric magenta dye forming coupler latexes formed from triazole and tetrazole monomers. Helling et al. (U.S. Pat. No. 4,756,998) disclose the preparation of polymeric couplers which contain at least one urethane or urea group. Yamanouchi et al. (U.S. Pat. No. 4,874,689) disclose the preparation of polymeric couplers utilizing chain transfer agents of eight or more carbon atoms. Helling (U.S. Pat. No. 4,921,782) discloses the preparation of polymeric magenta dye forming couplers, wherein the magenta coupler monomer contains a carboxyl group. Maekawa and Hirano (U.S. Pat. No. 4,946,771) disclose the preparation of polymeric couplers formulated with certain advantageously incorporated coupling and noncoupling comonomers.
Dappen and Bowman (U.S. Pat. No. 5,015,566) disclose the preparation of polymethacrylate latexes that reduce pressure sensitivity in tabular grain photographic elements.